2-Ethylhexanoic acid
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| Names | |
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| Preferred IUPAC name
2-Ethylhexanoic acid[1] | |
| Identifiers | |
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3D model (JSmol)
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| 1750468 | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.005.222 |
| EC Number |
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| MeSH | 2-ethylhexanoic+acid |
PubChem CID
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| RTECS number |
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C8H16O2 | |
| Molar mass | 144.214 g·mol−1 |
| Appearance | Colorless liquid |
| Density | 903 mg mL−1 |
| Melting point | −59.00 °C; −74.20 °F; 214.15 K |
| Boiling point | 228.1 °C; 442.5 °F; 501.2 K |
| log P | 2.579 |
| Vapor pressure | <1 Pa (at 25 °C) |
| Acidity (pKa) | 4.819 |
| Basicity (pKb) | 9.178 |
Refractive index (nD)
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1.425 |
| Thermochemistry | |
Std enthalpy of
formation (ΔfH⦵298) |
−635.1 kJ mol−1 |
Std enthalpy of
combustion (ΔcH⦵298) |
-4.8013–4.7979 MJ mol−1 |
| Hazards | |
| GHS labelling: | |
  
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| Danger | |
| H312, H318, H361 | |
| P280, P305+P351+P338 | |
| Flash point | 114 °C (237 °F; 387 K) |
| 371 °C (700 °F; 644 K) | |
| Explosive limits | 0.9–6.7% |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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| Related compounds | |
Related compounds
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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2-Ethylhexanoic acid (2-EHA), commonly known as octoic acid,[2] is the organic compound with the formula CH3(CH2)3CH(C2H5)CO2H. It is a carboxylic acid that is widely used to prepare lipophilic metal derivatives that are soluble in nonpolar organic solvents. 2-Ethylhexanoic acid is a colorless viscous oil. It is supplied as a racemic mixture.
Production
[edit]2-Ethylhexanoic acid is produced industrially from propylene, which is hydroformylated to give butyraldehyde. Aldol condensation of the aldehyde gives 2-ethylhexenal, which is hydrogenated to give 2-ethylhexanal. Oxidation of this aldehyde gives the carboxylic acid.[3]
Metal ethylhexanoates
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2-Ethylhexanoic acid forms compounds with metal cations that have stoichiometry as metal acetates. These ethylhexanoate complexes are used in organic and industrial chemical synthesis.[4] They function as catalysts in polymerizations as well as for oxidation reactions as "oil drying agents."[5] They are highly soluble in nonpolar solvents. These metal complexes are often described as salts. They are, however, not ionic but charge-neutral coordination complexes. Their structures are akin to the corresponding acetates.
Examples of metal ethylhexanoates
[edit]- Hydroxyl aluminium bis(2-ethylhexanoate), used as a thickener
- Tin(II) ethylhexanoate (CAS# 301-10-0), a catalyst for polylactide and poly(lactic-co-glycolic acid).[6]
- Cobalt(II) ethylhexanoate (CAS# 136-52-7), a drier for alkyd resins
- Nickel(II) ethylhexanoate (CAS# 4454-16-4)[7]
Regulations
[edit]2-Ethylhexanoic acid is banned in the EU for use in cosmetics.[8]
See also
[edit]References
[edit]- ^ "2-ethylhexanoic acid - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification and Related Records. Retrieved 21 February 2012.
- ^ Economic Impact Analysis of Proposed Test Rule for 2-ethylhexanoic Acid (final) (epa Contract No. 68-01-6630) (Report). Environmental Protection Agency, Washington, DC. Office of Toxic. 2000.
- ^ Riemenschneider, Wilhelm (2002). "Carboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a05_235. ISBN 978-3527306732.
- ^ Mishra, Shashank; Daniele, Stéphane; Hubert-Pfalzgraf, Liliane G. (2007). "Metal 2-Ethylhexanoates and Related Compounds as Useful Precursors in Materials Science". Chemical Society Reviews. 36 (11): 1770–1787. doi:10.1039/B614334M. PMID 18213985.
- ^ Raju, Ravinder; Prasad, Kapa (2012). "Synthetic applications of 2-ethylhexanoic acid derived reagents". Tetrahedron. 68 (5): 1341–1349. doi:10.1016/j.tet.2011.10.078.
- ^ Coulembier, O.; Degee, P.; Hedrick, J. L.; Dubois, P. (2006). "Controlled Ring-Opening Polymerization to Biodegradable Aliphatic Polyester: Especially Poly(Β-Malic Acid) Derivatives". Prog. Polym. Sci. 31: 723–747. doi:10.1016/j.progpolymsci.2006.08.004.
- ^ Burrows, Cynthia J.; Wey, Shiow-Jyi (2001). "Nickel(II) 2-Ethylhexanoate". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn014m. ISBN 0-471-93623-5.
- ^ Commission Regulation (EU) 2023/1490 of 19 July 2023 amending Regulation (EC) No 1223/2009 of the European Parliament and of the Council as regards the use in cosmetic products of certain substances classified as carcinogenic, mutagenic or toxic for reproduction